Method and transport system for controlling a container flow

Description

[0001] The invention relates to a method for controlling a container flow and a transport system for carrying out the method.

[0002] It is known to convey objects in production plants on interconnected conveyors and to monitor the distance between the objects and to selectively change this distance by separately controlling individual conveyors in order to supply the objects to a downstream production machine with the most uniform spacing possible. For example, DE 10 2004 035 821 A1 describes several conveyor belts arranged one behind the other, with a gap between each. Elongated objects, at least longer than the gaps between the conveyors, are transported on the conveyor belts. To adjust the distances between the individual products, individual conveyors are selectively accelerated as long as each one carries only one product.Conveyor systems with conveyor belts connected in series, the speed of which can be adjusted independently of one another, are also known from DE 3 621 601 A1 and EP 1 280 720 B1. JP 2012 210998 A discloses a method for controlling a container flow, comprising the steps of: a) Continuous transport of containers without back pressure on conveyors arranged in series by means of overruns, which run side by side in the area of ​​the overruns or follow one another in a non-overlapping series; b) Monitoring the container flow with sensors to detect a tipped-over container or...for synchronizing a label feed or for monitoring a minimum backlog upstream of an upstream single-screw conveyor; c) Individual control of the conveyors for selective acceleration of containers; d) Temporary joint increase of the transport speeds of at least two of the conveyors, wherein step d) is carried out after step c), wherein a joint increase of the transport speeds means that the conveyors simultaneously have a transport speed increased compared to a base speed, whereby the conveyors do not necessarily have to run at the same transport speed.

[0003] In beverage bottling plants or similar facilities, serially linked conveyors are used, in particular, to couple upstream machines with a container discharge function to a downstream guide machine in a block-like configuration. The conveyors then convey the correct containers without back pressure, for example, into a back pressure zone formed at the inlet of the guide machine. The average operating and conveying speed of such a machine block is then determined by the guide machine. The machine with a discharge function could be, for example, an empty bottle inspector, a full bottle inspector, a bottle sorter, a bottle distribution system, a unit for removing broken or inverted containers, or similar equipment.The guiding machine is, for example, a filler, a labeling machine or any other rotary machine with a single-lane container inlet.

[0004] Due to the discharge function of the upstream machine, gaps inevitably occur in the container flow. To ensure continuous operation of the guide machine, these upstream gaps must be compensated for by temporarily increasing the operating speed of the discharge machine and the transport speed of the intermediate conveyors. It is known to monitor the area of ​​the conveyors, for example, for gaps requiring correction, and to accelerate all conveyors upstream of a detected gap together with the discharge machine in order to at least reduce the size of the gap. If the gap is only partially closed, this is repeated, if necessary, on at least one downstream conveyor.

[0005] A disadvantage of this method, which is fundamentally suitable for closing gaps, is that the diverting machine is briefly accelerated to a relatively high speed during each of these sub-steps and then returns to its normal base speed. These changes each involve a comparatively large speed fluctuation. This results in unstable operation of the diverting machine. Furthermore, the speed adjustment of this machine to its diverting rate and the operating speed of the guide machine is severely limited. In addition, the speed fluctuation requires a correspondingly large excess capacity of the machine compared to its base speed. Alternatively, the maximum diverting rate of the machine must be limited.

[0006] In contrast, it would be desirable to be able to operate the discharge machine more evenly in order to allow the overall product flow to be smoother, to reduce the required excess capacity compared to the normal basic operation of the machine, and / or to better adapt this machine to the required discharge rates and / or the working speed specified by a lead machine.

[0007] The stated problem is solved by a method according to claim 1. Accordingly, this method serves to control a container flow and comprises the following steps: a) Continuous transport of containers without back pressure on conveyors arranged in a row by means of overruns, which run side by side in the area of ​​the overruns or follow one another in a non-overlapping series; b) Monitoring of the container flow with non-contact sensors with regard to the occurrence of gaps requiring correction between adjacent containers, whereby gaps requiring correction are understood to be distances between the containers that exceed a specified maximum value; c) Individual control of the conveyors for the selective acceleration of containers that are following a gap identified as requiring correction in step b), so that the identified gap is reduced and at least one compensatory gap is created behind the containers;and d) Temporary simultaneous increase of the transport speeds of at least two of the conveyors, wherein step d) is carried out after step c), wherein a simultaneous increase of the transport speeds means that the conveyors simultaneously have a transport speed increased compared to a base speed, the conveyors not necessarily having to travel at the same transport speed; and wherein the transport speeds in step d) are increased together with the operating speed of a machine causing the gaps.

[0008] By performing step d) only after step c), the speed increase in step d) for a catch-up movement of the containers to completely close the gap downstream of the transporters can be reduced.

[0009] The gap requiring correction is divided into at least one smaller gap and the compensatory gap. Preferably, the original gap is thus distributed across several sections of the container flow. A final, simultaneous acceleration of the containers upstream of the original gap, including the discharge machine, is then possible on several conveyors at once and with a comparatively small velocity change. This results in a more uniform transport of the containers overall, as well as improved utilization and control of the discharge machine.

[0010] In the area of ​​the transfers, the conveyors run side by side, so that the containers, for example, run along guide rails from one conveyor to the next, or follow each other in a non-overlapping line.

[0011] According to the invention, the flow of water from the containers is scanned using non-contact sensors, in particular optical sensors such as light barriers. Gaps are detected based on the distances measured between the containers. According to the invention, gaps requiring correction are understood to be distances between the containers that exceed a predetermined maximum value.

[0012] According to the invention, individual control of the conveyors means that they can be accelerated to different transport speeds simultaneously or overlapping in time. A common increase in transport speed means that the conveyors simultaneously exhibit a transport speed increased compared to a base speed, whereby the conveyors do not necessarily have to travel at the same transport speed.

[0013] According to the invention, the transport speeds in step d) are increased together with the operating speed of a machine creating the gaps. Thus, the reduced speed increase compared to closing the gaps without creating compensatory gaps is also effective in the machine creating the gaps.

[0014] This reduces the excess capacity of the machine required for catching up containers. The result is a more consistent operation of the machine causing the gaps. Furthermore, the permissible discharge rate of the machine for proper operation can be increased. The machine causing the gaps is located upstream of the conveyors, or an inbound conveyor of the transport system is configured as a discharge conveyor for the machine causing the gaps. The machine creates the gaps in the container flow by diverting defective containers or similar items and is therefore also referred to as a diverting machine.

[0015] Preferably, the operating speed of the discharge machine is increased relative to a base speed that is adapted to a current or average discharge rate of the machine. This simplifies the control of the discharge machine, particularly for adapting it to the operating speed of a downstream guide machine.

[0016] Preferably, in step a), the containers are transported on at least two, and in particular three, conveyors of different lengths. This offsets compensatory gaps against each other in the container flow during repeated partial gap closures. In other words, this prevents an unwanted enlargement of gaps due to the superposition of compensatorily created gaps when individual conveyors are accelerated. The lengths of adjacent conveyors preferably differ from each other by at least 15 percent.

[0017] Preferably, the maximum transport speeds of the conveyors in step c) differ from each other by 5 to 50 percent. This allows for the creation of sufficiently large compensatory gaps at at least two transfer points and avoids excessive acceleration at the transition between two adjacent conveyors. This prevents the containers from tipping over at the transfer points.

[0018] Preferably, the transport speeds in step c) for the time-overlapping reduction of at least two detected gaps are limited to a predetermined maximum value. This prevents the accelerations for reducing a detected gap and for creating compensatory gaps in the area of ​​a specific overrun from adding up to impermissible values. Such an overlap can occur, for example, if during a partial gap closure by reducing a first gap, for example in the area of ​​a second and third conveyor, a second gap requiring correction is detected and reduced in the area of ​​the first conveyor.

[0019] Preferably, the container flow is fed into a backpressure zone downstream of the conveyors at the inlet of a guide machine. The container flow is thus unified without backpressure by means of the most uniform possible distribution of gaps and introduced into the backpressure zone in this manner. Therefore, the container flow with the uniformly distributed gaps can be conveyed more uniformly into the backpressure zone over a correspondingly long period with a comparatively small increase in the transport speeds of several conveyors than would be possible without the creation of compensatory gaps.

[0020] Preferably, step d) is triggered by the arrival of the reduced gap at the dynamic pressure area, as determined in step c). This allows the originally existing gap requiring correction to be distributed across the available conveyors, i.e., the entire available dynamic pressure-free area, before the speed increase is initiated, particularly by involving the outgoing machine. This minimizes the speed increase required for a catch-up movement upstream of the dynamic pressure area.

[0021] Preferably, in step b), distances between the containers in the inlet areas of the transfer units are measured, and gaps are classified as requiring correction if they exceed a predetermined maximum distance. Particularly advantageously, the container flow is scanned for gap detection at a distance upstream of the respective transfer unit that corresponds to the distance defined as requiring correction or deviates from it by no more than 20%. The measurement of the distances and the classification of the gaps preferably take place at all transfer units downstream of which a separately controllable conveyor is located.

[0022] Preferably, the container flow passes at least via a first transfer from a first to a second conveyor and via a second transfer from the second to a third conveyor. Furthermore, the container flow is then monitored at least at the second transfer to detect gaps requiring correction. In step c), the first and second conveyors then temporarily run faster than the third conveyor, and the second conveyor temporarily runs faster than the first conveyor. This results in a reduction of the detected gap at the second transfer during continuous operation of the conveyors, while a compensatory gap is created at the first transfer.

[0023] Preferably, the container flow is further monitored at the first overpass to detect gaps requiring correction, and in step c) the first conveyor temporarily runs faster than the second conveyor. A reduction of any further detected gaps can then be carried out successively.

[0024] The stated problem is also solved with a transport system according to claim 11, which is designed and comprises the following for carrying out the method according to at least one of the preceding embodiments: The invention comprises a pressure-free transport section comprising conveyors connected by means of a push-pull mechanism; a monitoring device formed on at least one push-pull mechanism for detecting gaps in the container flow requiring correction; and a control unit for controlling the transport speeds of the conveyors. According to the invention, at least two of the conveyors have different lengths.

[0025] Identified gaps can be reduced in the area of ​​the overrun while simultaneously creating at least one compensatory gap in the area of ​​another overrun located upstream. Identified gaps can thus be distributed across multiple gaps in the container flow. This allows subsequent catch-up movements of the transport system to close the gaps in the area of ​​a downstream guide machine with a lower velocity stroke.

[0026] Successively generated compensatory gaps are offset from one another in the container flow due to the different lengths of the conveyors. This prevents undesirable overlapping of gaps, especially the creation of compensatory gaps larger than the originally identified gaps. The length ratio between the longest and shortest conveyor is, for example, 1.2 to 1.8. Suitable length ratios for a group of three conveyors are, for example, 6:5:4.

[0027] Preferably, the control unit is designed to operate conveyors of different lengths at varying speeds, at least overlapping over time. This occurs during essentially continuous operation of the conveyors, i.e., without individual conveyors stopping. Successive gap closing and compensatory gap formation are thus enabled with high machine performance and a low risk of containers tipping over.

[0028] A pressureless transport section with at least three conveyors and at least two connecting transfer sections is particularly advantageous. A monitoring device for detecting gaps in the container flow requiring correction is then provided, at least at the outbound transfer section. Preferably, the transport system comprises at least three consecutive conveyors of different lengths. A transport system in which three conveyors of different lengths can be controlled to operate simultaneously at different transport speeds is particularly advantageous.

[0029] Preferably, the first or inbound conveyor is an outbound conveyor from a machine that creates the gaps or from a discharging machine. This allows for a particularly compact design of the transport system. The speed of the inbound conveyor is then adapted to the control system of the discharging machine.

[0030] The problem is solved using a machine block comprising the transport system according to one of the previous embodiments, a machine upstream of the transport system that creates the gaps, and a guide machine with an input-side back pressure zone downstream of the transport system. In this machine block, machines are rigidly connected to one another via transport systems, so that gaps occurring in the container flow must be closed for the continuous operation of a downstream guide machine by temporarily accelerating following containers into a back pressure zone. By definition, the transport system then performs a catch-up movement in the container flow.

[0031] A preferred embodiment of the invention is shown in the drawings. They show: Figure 1 shows a container flow through a transport system according to the invention during the shortening of a gap requiring correction at a first push-over; Figure 2 shows the container flow after partial gap closure and creation of a first compensatory gap; Figure 3 shows a further partial gap closure in the area of ​​a second push-over; Figure 4 shows the container flow after the further partial gap closure and creation of a second compensatory gap; Figure 5 shows a further partial gap closure in the area of ​​a third push-over; Figure 6 shows the container flow with further compensatory gaps created in the process; Figure 7 shows the container flow when a catch-up movement is triggered for complete gap closure; and Figure 8 shows the creation of compensatory gaps at push-overs between conveyors of different lengths.

[0032] As the Fig. 1As can be seen in the schematic representation, the transport system 1 according to the invention, in a preferred embodiment, comprises a pressureless transport section 1a with overhangs 2, 4, 6, 8 at the transition to conveyors 3, 5, 7, 9, each designed for the transport of containers B without pressure. The overhangs 2, 4, 6, 8 guide the containers B, for example by means of guide rails or the like (not shown), in a manner known per se, onto the conveyor located laterally downstream. The conveyors 3, 5, 7, 9 are driven by drive motors 3a, 5a, 7a, 9a and can be controlled separately by means of a control unit 10, which is schematically indicated.

[0033] On the input side, non-contact monitoring units 4a, 6a, 8a, for example in the form of light barriers, are provided at the transfer points 4, 6, 8. The monitoring units 4a, 6a, 8a measure distances between the containers B moving in the container flow in order to identify gaps 11 in the container flow that require correction.

[0034] The following describes, by way of example, how a gap 11 to be corrected is successively reduced by repeated gap shortening 12 and, with compensatory gap formation 13, is distributed among several compensatory gaps 14 to 17 during continuous transport in the area of ​​the overthrusts 2, 4, 6, 8. The gaps are not shown to scale in the figures. For clarity, drive components that are temporarily accelerated relative to the base velocity of the transport system 1 are shown with a black fill.

[0035] Following the pressureless section 1a, a pressure zone 18 is formed for the inlet of the containers B to a guide machine 19 located downstream of the transport system 1. The guide machine 19 receives the container flow as a continuous sequence of the containers B.

[0036] In the Figure 1 Furthermore, upstream of transport system 1, a machine 20, linked to it, is shown, which creates the gaps 11 by diverting defective containers or the like from the container flow. A discharge conveyor 21 with a separate drive motor 21a is assigned to the gap-creating or diverting machine 20, which transfers the containers B to the first conveyor 3 via an inlet-side transfer unit 2.

[0037] In the figures, gap reductions 12 are indicated by converging block arrows. Compensatory gap formations 13 are indicated by outward-pointing block arrows in the area of ​​the respective overlaps.

[0038] The Figure 1 In the area of ​​the first conveyor 3 and a subsequent first pusher 4, a gap 11, classified as requiring correction, is shown. This gap was previously created by the upstream blocked machine 20 through the diversion of containers. The gap 11 is detected in the entrance area of ​​the first pusher 4 using the associated monitoring unit 4a, by measuring the length of the gap 11 from the container B1 preceding it.

[0039] If the distance to the preceding container B1 exceeds a predefined value, the gap 11 is classified as requiring correction, and the first conveyor 3 is temporarily and selectively accelerated at a suitable time. A suitable time is, for example, when containers B2 and B3, which are following the gap 11, are on the first conveyor 3 and can be accelerated relative to the container B1 preceding the gap 11.

[0040] The temporary acceleration of the first conveyor 3 causes a shortening of the gap 12 at the downstream overhang 4 and a compensatory gap formation 13 at the upstream overhang 2. This compensatory distribution of gaps 11 requiring correction in the container flow can be successively carried out with several conveyors 3, 5, 7, 9 temporarily running at different speeds at the associated overhangs.

[0041] The Figure 2 shows a state after the trailing containers B2, B3 have been selectively accelerated relative to the leading container B1, i.e., after the acceleration described in the Figure 1 The indicated gap reduction 12. From the original gap 11, a shortened gap 11a remains. This is then checked downstream for the need for correction.

[0042] Due to the temporary acceleration of the first conveyor 3, a first compensatory gap 14 has been created at the inbound overrun 2. The originally existing gap 11 requiring correction is thus divided between the shortened gap 11a and the first compensatory gap 14. In the Figures 1 and 2 In the partial step shown, the gap 11, which was originally identified as needing correction, is thus partially closed.

[0043] In the area of ​​the second overhang 6, a monitoring unit 6a is also present, which monitors the container flow in the same way with regard to the occurrence of gaps requiring correction, as described above for the first overhang 4. As the Figure 3 As indicated, the gap 11a, shortened by partial gap closure, is also recognized as requiring correction in the area of ​​the second push-over 6. Consequently, the second conveyor 5 with the containers B2 and B3 on it is temporarily accelerated relative to the third conveyor 7.

[0044] In addition, the first conveyor 3 is also temporarily accelerated relative to the third conveyor 7, but with a smaller speed difference than the second conveyor 5. This results in at least one further compensatory gap 13 in the area of ​​the first overrun 4 and / or in the area of ​​the inbound overrun 2, resulting in at least one second compensatory gap 15.

[0045] The state after the temporary acceleration of the first and second transporters 3, 5 relative to the third transporter 7 is in the Figure 4 As shown, the previously partially closed gap 11a was subsequently shortened again by the further reduction of the gap 12 according to Figure 3 The further shortened gap 11b between containers B1 and B2.

[0046] Upstream of the further shortened gap 11b, the first compensatory gap 14 and the second compensatory gap 15 can be seen in the container flow. The lengths of the further shortened gap 11b and the compensatory gaps 14 and 15 add up to the length of the originally existing gap 11 requiring correction.

[0047] As the Figure 5As indicated above, monitoring of the container flow for gaps requiring correction can optionally be carried out in the area of ​​the third overpass 8, as described above. It is then possible to shorten the shortened gap 11b further if necessary and / or to create additional compensatory gaps 16, 17 in the area of ​​the first overpass 4 and / or in the area of ​​the inlet-side overpass 2 by means of additional gap formations 13. For this purpose, the first three conveyors 3, 5, 7 are temporarily accelerated to different transport speeds relative to the fourth conveyor 9, following the procedure described above.

[0048] The Figure 6 indicates the state after the optional creation of the compensatory gaps 16, 17, whereby the originally existing gap was further reduced to the final gap 11c, which merges into the dynamic pressure area 18. How Figure 6As can be seen, the container flow was altered by the temporary acceleration of at least the first conveyor 3 and the second conveyor 5 by forming at least one compensatory gap 14 compared to the flow in the Figure 1 The depicted container flow is distributed more evenly in the pressureless transport section 1a.

[0049] The Figure 7 shows a state in which the arrival of the compensatorily reduced final gap 11c is detected by means of a monitoring unit 18a, for example a light barrier, formed at the entrance to the dynamic pressure area 18, in order to trigger a catch-up movement of the following container stream by joint temporary acceleration of at least the conveyors 3, 5, 7 and the upstream blocked machine 20.

[0050] For this purpose, the discharge machine 20 with its discharge conveyor 21 and the conveyors 3, 5, 7, and optionally also the conveyor 9, temporarily run faster than a predetermined base speed of the discharge machine 20. This causes all gaps present on the conveyors 3, 5, 7, 9, i.e., the compensatorily reduced final gap 11c and the compensatory gaps 14 to 17 generated in the dynamic pressure area 18, to be pushed together with complete gap closure.

[0051] This catch-up movement ensures that there are always sufficient containers B available in the back pressure area 18 and the subsequent guide machine 19 for the continuous processing of the container flow.

[0052] The basic speed of the discharge machine 20 is set, for example, depending on a discharge rate of the machine 20, so that on average sufficient container B is conveyed into the dynamic pressure area 18.

[0053] Because the complete closing of the gap, including the outgoing machine 20, only takes place after the creation of compensatory gaps, the catch-up movement, including all conveyors 3, 5, 7, 9 of the zero-pressure transport section 1a, can be distributed over a comparatively long period of time and consequently take place with a smaller speed increase relative to the basic speed of the machine 20.

[0054] This means that machine 20 requires less excess capacity (in terms of speed reserve) to perform the catch-up movement than would be the case with a conventional gap closure system according to the state of the art. Furthermore, due to the more consistent operation, a base speed for machine 20 can be set that is adapted to its current discharge rate. For example, if the discharge rate of machine 20 decreases, it can be operated at a lower base speed to maintain the required container flow to supply the guide machine 19. If the discharge rate of machine 20 increases, for example due to lower product quality, the base speed of machine 20 can be increased to compensate for the increased discharge rate.

[0055] In simplified terms, unlike in known methods, the diverting machine 20 no longer has to keep pace with every acceleration of the downstream conveying units 3, 5, 7, 9, so that the adjustment of the basic speed of the diverting machine 20 to the divert rate and the working speed of the guide machine 19 is simplified overall and the need for excess capacity to perform catch-up movements decreases.

[0056] The Figure 8This illustrates that the successive creation of compensatory gaps is facilitated by the fact that the conveyors 3, 5, 7 have different lengths L3, L5, L7. As a result, the gap formation 13 at the transfers 4, 6, 8 occurs at points offset from one another in the container flow. This prevents the gap formation 13 from repeatedly occurring at the same point in the container flow during successive partial gap reductions 12-4 at the first transfer 4, 12-6 at the second transfer 6, and 12-8 at the third transfer 8. Therefore, the gap generation 13 cannot create a compensatory gap larger than the originally existing gap 11 requiring correction.

[0057] For this purpose, preferably at least three consecutive conveyors, for example conveyors 3, 5, 7, are designed with different lengths L3, L5, L7. Suitable length ratios of conveyors 3, 5, 7 are, for example, L3:L5:L7 equal to 6:5:4.

[0058] The method shown in the figures could, in principle, also be carried out by gap detection at the inlet-side feeder 2 in combination with the first feeder 4 and the second feeder 6. In this case, the outfeed conveyor 21 of the discharging machine 20 would take over the previously described function of the first conveyor 3, the first conveyor 3 would take over the function of the second conveyor 5, and so on.

[0059] Such a configuration would be advantageous in confined spaces. However, the discharge conveyor 21 for gap formation 13 can then only be accelerated to a limited extent, since the operating speed of the discharge machine 20 is only to be changed by a comparatively small increase in speed relative to its base speed. Furthermore, the ability to adjust the discharge machine 20 to an existing discharge rate would be limited.

[0060] Nevertheless, the speed increase required for the catch-up movement to finally close the gap can also be achieved by generating compensatory gaps on the basis of a combination of the first and second conveyors 3, 5 with the discharge conveyor 21 of the machine 20 causing the gaps.

[0061] This results in a more consistent overall operation of the machine block, consisting of the discharge machine 20, the transport system 1, and the guide machine 19. Furthermore, the need for excess capacity in the discharge machine 20 to perform the necessary catch-up movement on the zero-pressure conveyors 3, 5, 7, and 9 is reduced.

Claims

1. A method for controlling a container flow, comprising the steps of: a) continuous transportation of containers (B) without dynamic pressure on carriers (3, 5, 7, 9) that are arranged in rows by means of overlays (2, 4, 6, 8) and that run next to each other in the area of the overlays or follow each other in a row in a non-overlapping manner; b) monitoring the container flow with non-contact sensors with regard to the occurrence of gaps (11) between adjacent containers (B1, B2) that require correction, wherein the gaps requiring correction are to be understood as meaning distances between the containers that exceed an assigned maximum value; c) individual control of the carriers for the selective acceleration of containers (B2, B3) that are trailing behind a gap recognized as requiring correction in step b), so that the gap is reduced and at least one compensatory gap (14) is created behind the containers; d) a temporary joint increase in the transport speeds of at least two of the carriers, wherein step d) being carried out after step c), a joint increase in the transport speeds being understood to mean that the carriers simultaneously have an increased transport speed compared to a basic speed, whereby the carriers do not necessarily have to run at the same transport speed; and wherein the transport speeds in step d) are increased together with the operating speed of a machine (20) causing the gaps.

2. The method according to claim 1, wherein the operating speed is increased with respect to a base speed of the machine (20), which is adapted to a current or averaged ejection rate of the machine (20).

3. The method according to one of the previous claims, wherein the containers (B) are transported in step a) on at least two, in particular three, carriers (3, 5, 7) of different lengths.

4. The method according to at least one of the previous claims, wherein the maximum transport speeds of the carriers (3, 5, 7, 9) in step c) differ by 5 to 50%.

5. The method according to at least one of the previous claims, wherein the transport speeds in step c) are limited to a predetermined maximum value for the temporally overlapping reduction of at least two detected gaps (11).

6. The method according to one of the previous claims, wherein the container stream is supplied to a back pressure area (18) following the carriers in the inlet of a guide machine (19).

7. The method according to claim 6, wherein step d) is triggered by the arrival of the gap (11c), reduced in step c), at the back pressure area (18).

8. The method according to one of the previous claims, wherein in step b) distances between the containers (B1, B2) are measured in inlet regions of the overlays (4, 6, 8) and gaps (11, 11a, 11b) are classified as requiring correction from a predetermined maximum distance.

9. The method according to at least one of the previous claims, wherein the container flow passes at least over a first overlay (4) from a first to a second carrier (3, 5) and over a second overlay (6) from the second to a third carrier (7) and is monitored at least at the second overlay for detecting the gaps requiring correction, and wherein in step c) the first and second carrier run temporarily faster than the third carrier and the second carrier runs temporarily faster than the first carrier.

10. The method according to one of the previous claims, wherein the container stream is further monitored at the first overlay (4) for detecting gaps requiring correction and the first carrier (3) runs temporarily faster than the second carrier (5) in step c).

11. A transport system (1) for carrying out the method according to at least one of the previous claims, comprising: - a zero-pressure accumulation transport section (1a) comprising carriers (3, 5, 7, 9) connected by means of overlay (4, 6, 8), wherein at least two of the carriers have different lengths (L3, L5, L7); - a monitoring unit (4a, 6a, 8a) formed on at least one overlay for detecting gaps (11) in the container flow that require correction; and - a control unit (10) for controlling the transport speeds of the carriers, which is adapted to carry out the steps of the method according to at least one of the previous claims.

12. The transport system according to claim 11, wherein the control unit (10) is configured to allow the carriers of different lengths to run at least overlapping in time at different transport speeds.

13. The transportation system according to claim 11 or 12, wherein the input-side carrier is an outlet carrier (21) of a machine (20) causing the gaps.

14. A machine block with the transport system (1) according to one of claims 11 to 13 and with a machine (20) causing the gaps upstream of the transport system and with a leading machine (19) with an input-side dynamic pressure area (18) downstream of the transport system.